In general, the semiconductor light-emitting element having a compound semiconductor layer such as a group III-V compound semiconductor layer is prepared as a light-emitting element chip by forming the compound semiconductor layer on a substrate made of a sapphire single crystal or the like, further providing an anode, a cathode and the like, grinding and polishing a surface-to-be-ground of the substrate, and thereafter cutting into an appropriate shape (refer to Patent Document 1).